Thermocatalytic CO2 Hydrogenation to Liquid Fuels

Thermocatalytic CO2 hydrogenation to liquid fuels, including ethanol and liquid hydrocarbons, has drawn global attention recently as a potential strategy to decrease CO2 emissions and reduce the consumption of and dependence on fossil fuels. The nature of catalyst has an important impact on the conversion and selectivity and clarifying the catalyst structure-performance relationship is essential to synthesize the desired liquid products. Compared with C1 products, the generation of ethanol and liquid hydrocarbons with two or more carbon atoms is more difficult owing to the high energy barrier for C–C coupling. Current studies show that the interfacial catalysts are suitable for CO2 hydrogenation to ethanol and the active interface is generally responsible for key CO* insertion, while the metal/carbide catalysts and oxide-zeolite tandem catalysts play vital roles in that to liquid hydrocarbons. In this chapter, we discuss the latest advances in the representative noble metals, transition metals and their carbides, and modified Cu-based catalysts for the synthesis of ethanol, Fe–, Co-based catalysts as well as tandem catalysts for that of long-chain hydrocarbons. Fundamental understanding on active sites, structural evolution, CO2 activation, and reaction mechanism are discussed based on computational and experimental results. On this basis, we discuss some concepts on catalyst design as well as the challenges and opportunities for its development and potential industrial applications.